1. Field of the Invention
The present invention relates to a storage apparatus allowing new data to be additionally written into a storage area already used for holding previously stored write data and relates to a storage system employing the storage apparatus.
2. Description of the Related Art
A flash memory is a storage apparatus allowing data stored therein in page units.
A special flash memory allows data of a plurality of pages to be stored in a page by converting the data into multi-value data (refer to Japanese Patent Laid-open No. 2008-003684 and PCT Patent Publication No. WO2007-000862).
In the flash memory allowing data of a plurality of pages to be stored in a page by converting the data into multi-value data, for example, data of one page is written by a host apparatus by storing the data into an empty page in a first write access whereas data of the next page is additionally written by the host apparatus by storing the data into the page, in which the data of the first one page has already been stored previously, in a second write access.